My first impression when I read the heading: Oh no, not another ebay.de!
I don't know about international ebay sites, but the german one has removed the "downvotes" for vendors. Vendors can send a neutral or positive rating, buyers can additionally send a negative rating. Sure, the rating system was abused by some people, but without any way to tell others that a buyer shows unwanted behaviour, the rating system on ebay.de is essentially useless for vendors. And neutral is the "new negative".
What does that mean for perlmonks? There is no neutral vote, just up and down. Remove down and you get a completely useless tool, just like the page visit counters on every web page in the 1990s.
I use the voting tool as a shotcut to "punish" bad behavior or really stupid posts with downvotes, and to reward good posts. Nothing more, nothing less.
Yes, there are trolls around here, some plain stupid ones, and a few some very clever ones. The former disappear rater quickly, but the clever ones are harder to handle. I downvote troll postings of both kinds, even if that does not hurt the XP of the clever ones much. But even if I prefer upvoting, I would really miss the downvote function.
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)